Preparation of fluorinated cyclobutenyl alkyl ether copolymers

ABSTRACT

Disclosed are highly fluorinated polymers of the formula:   In the above formula, Rf and Rf&#39;&#39; are straight or branched chain perfluoroalkyl groups or perfluoroalkyl ethers having a combined number of carbon atoms totaling from 3 to 20, n is a number of from 2 to 10,000 representing the degree of polymerization and the ratio of x:y ranges from 0.001:1 to 1000:1. The polymers are thermally stable and flexible. In addition they contain double bonds as crosslinking sites.

Unite States Anderson et al.

atent Aug. 19, 1975 PREPARATION OF FLUORINATED CYCLOBUTENYL ALKYL ETHER COPOLYMERS [75] Inventors: Richard W. Anderson, Englewood,

Colo; Hughie R. Frick, Midland, Mich.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

1221 Filed: Mar. 21, 1974 21 Appl. No.: 453,652

Related US. Application Data [62] Division of Ser. No. 231,404, March 2, 1972, Pat.

[52] U5. Cl 204/163 R [51] Int. Cl B0lj 1/10 [58] Field of Search 204/163 R [56] References Cited UNITED STATES PATENTS 3,228,864 1/1966 Mastrangelo 204/l63 R Primary E.\'aminerLeland A. Sebastian Attorney, Agent, or FirmEdward E. Schilling 7 ABSTRACT Disclosed are highly fluorinated polymers of the formula:

3 Claims, No Drawings PREPARATION OF FLUORINATED CYCLOBUTENYL ALKYL ETHER COPOLYMERS CROSS-REFERENCE TO RELATED APPLICATION This is a division of application Ser. No. 231,404 filed Mar. 2, 1972, now US. Pat. No. 3,840,603.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The present invention comprises highly fluorinated polymers of the formula:

III:

and a method for their preparation. In the above formula, R; and R,-' are straight or branched chain perfluoroalkyl or perfluoroalkyl ethers having a combined number of carbon atoms of from 3 to 20, n is a number of from 2 to 10,000 representing the degree of polymerization and the ratio of xzy ranges from 0.001 :1 to 1000: 1.

DETAILED DESCRIPTION The polymers are prepared by a coupling type polymerization in which mercury and ultraviolet light are employed as reaction promoters. The reaction time may range from 1 hour to 6 months or more depending on the degree of polymerization desired. The reaction 1n the above formula, R, and R;' are perfluoroalkyl groups or perfluoroalkyl ethers selected so that the total number of carbon atoms in the lR,OR -I group ranges from 3 to 20. Specific examples of R; and R are perfluorinated methyl, propyl, pentyl, isooctyl, decyl, dodecyl, tetradecyl and hexadecyl. The R and R, groups may independently be perfluoroalkyl ethers examples of which are perfluorinated ethyl propyl ether, propyl pentyl ether, and ethyl pentyl ether.

10 The preferred polymers of the instant invention are those in which n is a number from 2 to 1,000, the combined number of carbon atoms in R, and R, is from 3 to 11 and the ratio of xzy ranges from 1:5 to 5:1. When a liquid or rubbery polymer is desired, the 1:5 ratio is 15 selected.

The iodine terminated perfluoro cyclobutene is prepared as set out in co-pending application 869,338. The iodine terminated ether may be prepared by the process disclosed in U.S. Pat. No. 3,505,411. Iodine 2o terminated polyethers are also prepared by reacting a difunctional perfluoroacetyl fluoride with tetrafluoro ethylene in the presence of potassium fluoride and i0- dine. This preparation is indicated by equations 11 and III:

In the above reaction n is a number from 1 to 14 thus providing a diether having up to carbon atoms.

A method for preparing iodine terminated monoethers is represented by equations IV and V:

ll ll 1 V: I(CF O CF 1+ 2Agl 2CO In the above equation, m n is equal to from 3 to 20. The invention is further illustrated by the following examples.

EXAMPLES l5 In each of the following examples, polymers were prepared by reacting perfluoro 3,4-diiodocyclobutene with perfluoro-1,1 1-diiodo-3,9-dioxaundecane to form a polymer of the formula:

temperature may vary from 30C. to 250C. with a temperature of from 20 to 150C. being preferred.

The reaction was carried out in a glass pressure vessel containing excess elemental mercury. In each run The monomeric materials are iodine terminated in so CCIQFCC IF-z was employed as solvent. The reaction order for the coupling reaction to proceed. The general reaction is set out in equation I.

let-4 mass was irradiated with ultraviolet light while being cooled to 30 to 40C. with a stream of air. After the reaction had gone to completion, as indicated by the presence of black mercuric iodide, the reaction mixture was centrifuged, with the freon soluble portion of purified by vacuum subliming the mercury and mercury iodides from the polymer.

The ratio of perfluorobutene moieties to perfluoroether moieties in the polymer are modified by adjusting the stoichiometry. The degree of polymerization in each run was determined by iodine end group analysis.

The reactants and products of examples l are set out in Table 1.

Due to their high fluorine content these compounds exhibit good thermal and oxidation resistance. The liquid polymers are useful as hydraulic fluids for high temperature applications such as breaking systems. The solid polymers can be used to form ablatives and gaskets for uses in which stability is essential.

20, n is a number from 2 to 10,000 representing the degree of polymerization and the ratio of xzy ranges from 0.001 :1 to 1000: 1 which comprises reacting in the presence of mercury and ultraviolet light a diiodo perfiuorocyclobutene of the formula with an iodo terminated perfluoroalkyl ether of the formula lR,OR;-l wherein R, and R are straight or branched chain perfluoroalkyl groups or perfluoroalkyl ethers having a combined number of carbon TABLE I REACTION PARAMETERS PRODUCT PARAMETERS Time, Degree of Physical Cyclobutcne (X) Ether (Y) Ratio XzY Mercury gm. Solvent Hour Polymerization Properties 1. 11.6 gm. 5.0 gm.

(0.034 mole) (0.0068 Mole) 5:1 10.0 50 ml. 309 n= 35 Soft Solid 2. 0.412 gm. 4.0 gm. Mobile non (0.00109 mole) (0.0054 Mole) 1:5 10.0 ml. 76 n= 350 volatile liquid 3. 1.285 grn. 5.0 gm. Mobile non- (0.0034 mole) (0.0068 Mole) 1:2 10.0 25 ml. 1 12 n= 300 volatile liquid 4. 2.57 gm. 5.0 gm. Mobile non- (0.0068 mole) (0.0068 Mole) 1:1 10.1 25 ml. 196 n= 300 volatile liquid 5. 5.14 5.0 gm. Mobile non- (0.0136 mole) (0.0068 Mole) 2:1 10.2 25 ml. 177 n=- 160 volatile liquid We claim: atoms totaling from 3 to 20, said process being further 1. A process for the preparation of a highly fluorinated polymer of the formula:

wherein R; and R, are straight or branched chain perfluoroalkyl groups or perfluoroalkyl ethers having a combined number of carbon atoms totaling from 3 to UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT N0. 3,900,380

DATED August 19, 1975 INVENTOR(S) Richard W. Anderson and Hughie R. Frick It is certified that error appears in the ab0veidentified patent and that said Letters Patent i are hereby corrected as shown betow:

On page 1, under Abstract, correct the formula as follows:

t/x A; R 1

Nil) X K Column 1, line 35, in the formula under Summary of the Invention, underline the E as in the above formula.

Column 1, line 65, correct the formula as follows:

I: I I

X l Y IR -O-R -1 I F/ R OR I n I-IgI Q f f 2 Y i X Y n UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,900,380 Page 2 DATED August 19, 1975 INVENTOR(S) Richard W. Anderson and Hughie -R.- Frick It is certified that error appears in the aboveidentitied patent and that said Letters Patent are hereby corrected as shown below:

In Column 2, correct line 43 as follows:

In column 2, under Examples l5, correct the formula as follows:

.L k \CF CF -Ot-CF -+5-O-CF CF I In column 3, under Claim 1, underline the E in the formula, as in the above formula, as follows:

I L \R OR I X Y n UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,900, 380 Page 3 DATED August 19, 1975 INVENT R( 1 Richard W. Anderson and Hughie R. Frick It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below;

In column 4, correct the formula in Claim 1 as follows:

ninth D a) of December I 9 75 [SEAL] A ttest:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ufPaten ts and Trademarks 

1. A PROCESS FOR THE PREPARTION OF A HIGHLY FLUORINATED POLYMER OF THE FORMULA: I-((PERFLUOROCYCLOBUTENYLENE)X-(RF-O-RF'')Y)N-I DI(I-)PERFLUOROCYCLOBUTENE WHEREIN RF AND RF'' ARE STRAIGHT OR BRANCHED CHAIN PERFLUOROALKYL GROUPS OR PERFLUOROALKYL ETHERS HAVING A COMBINED NUMBER OF CARBON ATOMS TOTALING FROM 3 TO 20, N IS A NUMBER FROM 2 TO 10,000 REPRESENTING THE DEGREE OF POLYMERIZATION AND THE RATIO OF X:Y RANGES FROM 0.001:1, WHICH COMPRISES REACTING IN THE PRESENCE OF MERCURY AND ULTRAVIOLET LIGHT A DIIODO PERFLUOROXYCLOBUTENE OF THE FORMULA
 2. The process of claim 1 wherein the temperature is maintained at a level from -30* to 250*C.
 3. The process of claim 1 wherein the perfluorocyclobutene and iodo terminated perfluoroalkyl ether are reacted in a solvent capable of disolving the reactants and the resulting product. 